Six Pack Carbs?

I think the Ford tripowers were mechanical secondary, with a progressive linkage. IF you could find some at a reasonable price (UNlikely!) they could work.
I believe Corvette carbs are available new, for less money than the mopars, and they will definitely work. They are vacuum actuated secondary carbs, like the mopars, but they can run three corvette centers with a progressive linkage if the fuel bowls are changed.
There really is no such thing as a budget/inexpensive six pack setup.... for anything (Ford, Chevy, or mopar).